First offender Andrew Hart (53), who faces losing his sight, preyed on his victims when they were girls and went on to repeatedly rape one of them.
A judge at the High Court in Edinburgh told Hart that he was earlier found guilty of serious sexual offences against the three girls.
Judge Norman McFadyen said it was clear from the evidence which a jury must have accepted that he was "an opportunistic sex offender".
The judge said that a background report prepared on him not surprisingly assessed him as posing a continuing risk to children if he had unsupervised contact with them.
He ordered that Hart, a prisoner at Low Moss jail, should be jailed for six years and eight months then kept under supervision for a further three year period.
He also placed him on the sex offenders' register for an indefinite period.
Hart had denied the sex crimes at his earlier trial but was convicted of five charges of indecent behaviour, assault, sexual assault and rape committed between January 2007 and December 2018 at houses in Larbert and Stenhousemuir.
His youngest victim was aged 11 when the abuse began and he went on to hold her down and rape her.
Defence counsel Lorenzo Alonzi argued that Hart's age and disability were likely to reduce the chance of any further offending.
He said: "He is aware he is facing a lengthy custodial sentence. It will present a greater punishment for him that it would the ordinary prisoner."
He said that Hart has been told that he will ultimately lose his sight and at present letters sent to him in jail are put under the door for him.
Mr Alonzi said: "He has no ability to read them or get them read to him."
The judge said he took into account what was said on Hart's behalf, including his disability, but pointed out he was suffering with it when committing the abuse of two of the victims.
Speaking following the sentencing today, Detective Inspector Yvonne O'Rourke at Forth Valley Public Protection Unit said: “The horrific crimes which Andrew Hart committed on the young victims will live with them for ever, and I would like to commend them for coming forward and speaking up. I hope that the sentencing today will offer them some comfort as they seek to put their ordeals behind them.
"We welcome the sentence, and his placement on the Sex Offenders register means that he will be the subject of monitoring and supervision in efforts to restrict his ability to harm anyone else.
"Police Scotland is committed to bringing all perpetrators of sexual abuse to justice, regardless of the passage of time. It is never too late to report these types of crimes and we would urge anyone who wishes to report sexual crime, regardless of when it occurred, to contact us on 101 so we can conduct a thorough investigation.”